Guarding the entrance to the room ahead is a metallic, pillar-like structure. You can see numerous mechanical gizmos and cogs whirring about, and small orbs of arcane energy orbit the object. Inspecting more closely, you can see that it is divided into an upper and lower section, which seem to rotate independently of one another. Each section has a pair of glowing magenta-colored rods attached which converge into a point.

The arcano-turret is a security drone designed by elven techno-mages--individuals proficient in both magic and machinery. The machine is magically imbued with a very weak artificial intelligence--just enough to enable it to follow a set of instructions to determine target priority. The elves typically place these devices at the gates of their fortresses or at the entrances to high-security areas, such as prisons or treasure vaults. An arcano-turret draws in the latent magical energies within the earth to power its attacks. The techno-mages who designed these sentries cleverly implemented a dual-core system: the arcano-turret can simultaneously identify and fire spells at two different targets using a seperate target priority program for each.

Arcano-turrets speak Common, although their vocabulary is limited to a handful of programmed phrases related to their duty (common examples include "This is a restricted area. Please provide password or other proof of authorization", "You are unauthorized. Please leave the premises", and "Intruder alert!").

An arcano-turret will attack any creature that threatens it or attempts to approach it without providing some sort of authorization to enter whatever area it protects (usually in the form of a password). The turret's dual-core system allows it to simultaneously identify, prioritize, and attack two different targets. The lower half prioritizes melee opponents, and generally uses spells designed to stun and hinder targets. The upper half prioritizes spellcasting opponents, and generally uses direct-damage attacks. For instance, if fighting a party consisting of a barbarian, rogue, cleric, and wizard, the lower half will target the rogue and barbarian and prefer spells such as black tentacles and solid fog, while the upper half targets the cleric and wizard using magic missile and lightning bolt.

Mechanoid: Although technically a creature, the arcano-turret's largely mechanical nature causes it to take damage as if it were an object. This means, among other things, that it has a Hardness value that it subtracts from damage it takes, that it takes half damage from electricity and fire and one-fourth damage from cold, and that it takes half damage from most ranged weapons. Spells and abilities that cannot target objects can still target the arcano-turret. If a spell or ability can target either creatures or objects, but affects objects differently from creatures, it affects the arcano-turret as either a creature or an object (whichever would be more advantageous to the turret). Spells that can only target objects cannot target the arcano-turret.

Stationary: Although it has a Dexterity score, the arcano-turret is built into the ground and cannot move. It always counts its Dexterity as 0 for the purpose of determining its AC. It cannot be bull rushed, overrun, or rendered prone in any way, except by a creature with a Strength score of at least 27 or by 1000 lbs of force. If uprooted by such a force, the arcano-turret ceases to function. The arcano-turret cannot initiate a grapple.

Spell Resistance (Ex): An arcano-turret has spell resistance 16.

Defense Mechanisms (Ex): Rotating shield-like structures, whirring gears, flailing machinery, and a field of arcane energy together mimic the defensive maneuvers of a seasoned warrior. The arcano-turret never provokes attacks of opportunity for using its spell-like abilities. It can use spell-like abilities without penalty even while grappling.

Dual Core (Ex): The arcano-turret is divided into two segments, each with its own targeting programs and artificial intelligence imbuement. In a single round, each segment can cast a spell-like ability, and at different targets if so desired. The lower segment tends to target melee opponents. The upper segment tends to target ranged and spellcasting opponents. Each segment has its own spell list.

Blindsight (Su): In addition to its visual sensors, the arcano-turret is equipped with a magical motion sensing system that can pinpoint creatures with incredible accuracy through vibrations in the air and ground. A creature standing perfectly still and making no noise can hide from this motion sensor.

Spell-Like Abilities (Sp): The arcano-turret uses spell-like abilities as an eigth-level sorcerer. The save DC's against its spell-like abilities are Charisma based. Arcano-turrets will usually avoid using their higher-level attacks unless they are faced with a large group of enemies or they become heavily damaged.

An arcano-turret is constructed from steel, adamantine, and mithral. The materials cost 5000 gp. Creating the body requires a DC 22 Craft(Engineering) check. Anyone with at least 5 ranks in Knowledge (Architecture & Engineering) recieves a +2 synergy bonus on this check.

Once the body is assembled, two power cores must be inserted. These power cores are fashioned from deep crystal costing 500 gp apiece. Each must be specially sculpted using a DC 17 Craft (Jeweler) check. Once sculpted, the power cores must be programmed through a special ritual that requires a successful DC 18 Knowledge (Tactics) check and 1000 gp worth of miscellaneous arcane reagants per attempt. During this programming ritual, the creator specifies any passwords he wants the arcano-turret to recognize, as well as any phrases he wants the arcano-turret to be able to speak.

With the body assemled and the power cores imbued and inserted, the last step is to animate the arcano-turret. A steel foundation must be created, which will channel energies from the ground into the turret. This foundation is coated with deep crystal and embedded with magically imbued rivets. The entire foundation costs 1000 gp worth of materials. This foundation must be firmly planted into the ground. When a fully-constructed arcano turret is attached to a foundation using a DC 15 Craft (Blacksmithing) check and 1 hour of work, it becomes animated and fully operational. An arcano turret can be detached from its foundation by 1000 pounds of force, at which point it deactivates. The arcano-turret can then be moved and attached to any other foundation built for it, reactivating as soon as it is fully attached.

Several people may participate in the construction of an arcano-turret, with each providing the skill checks he/she is best at. At least one person must meet the prerequisites below.